The present invention relates to image contrast enhancement. More particularly, the present invention relates to image contrast enhancement for positioning or docking applications.
Positioning tasks may be performed using complex and expensive devices such as tachymeters or electronic theodolites. Such positioning devices can include one or more supplementary measurement components, for example, a digital camera or a laser. The digital camera or laser may be used for measurement purposes or to monitor an area of interest. In some cases, even if there is no laser on board, an off-the-shelf laser pointer (such as those used when making presentations to a group of people) may be attached to the object for which positioning is desired.
When using a laser, some type of receiver is required to receive the outputted laser beam for sensing or analysis. In particular, when both the laser and the receiver are located at the object for which positioning is relevant, a digital camera may be used in conjunction with one or more markers placed at known locations. The digital camera captures images of the marker and when the laser beam outputted from the laser impinges on the marker, both the marker and the laser beam are captured in an image, thus providing detection of the laser beam at a known location. Use of the digital camera and marker provides visual laser beam or laser spot recognition without the need for a specific laser receiver, such as a photo detector.
Typically, lasers and digital cameras included as supplementary components to overall complex positioning/measurement devices tend to be of low quality in order to keep costs down. The laser beams tend to have low beam intensity and small laser spot sizes, and/or the digital cameras tend to have significant noise components with insufficient image processing capabilities. Consequently, laser beams may appear almost invisible on captured images and laser beams impinging on a marker may not be detectable.
Even when higher quality lasers and/or digital cameras are used, either as supplementary components or stand alone positioning devices, sophisticated image processing may be required to accurately detect the presence of the laser beam at the marker. This may be the case where ambient lighting is strong or there are other interference effects.
Thus, it would be beneficial to provide a simple and inexpensive method and system for detecting a laser beam at a position marker. It would be beneficial to provide accurate laser detection even using inexpensive and/or low quality laser source and/or imaging apparatus. It would be beneficial to provide image contrast enhancement using standard image scanning. It would be beneficial to provide accurate position detection without requiring additional signal processing. It would be beneficial to provide simple and inexpensive positioning, orientation, or machine control features.